Passive access/passive start systems that use permanent orientations and synchronization words to detect attacks on relay stations of the range extension type

摘要

A system for providing an in-service control over a vehicle includes a first network device and a control module. The first network device includes polarised antennas; a transmitter which sends an initiator package via the polarised antennas from the vehicle to a second network device comprising a synchronization access word and a CW sound, one of the first and second network devices within the vehicle being implemented, the other of the first and second network devices is a portable access device,and at any time at least one of the polarised antennas is not cross-polarised with an antenna of the second network device; and a receiver that receives a response package from the second network device that includes the synchronization access word and the first CW sound. A control module determines a difference in RTT between the initiator and response packages and detects a relay attack of the range extension type.